Magnetic Beads from US Biologicals

Magnetophoresis is the motion of dispersed magnetic particles relative to a fluid under the influence of a magnetic field. The movement of magnetic particles can be used to detect or isolate specific components in the fluid, using specific binding and or capture.

Magnetic bead separation is one of the simplest, affordable and best technologies for detection and purification of DNA, proteins and antibodies. Magnetic beads speed up and simplify the process. In addition they can be re-activated and used again for some applications. A large advantage is that after initial manual handling, the same purification or detection can be automated easily and conversion to a high-throughput system (e.g. robot is feasible).

Separation is highly dependent on the demands of the assay and the environment (fluid, suspensions, blood) in which it takes place. Shorter separation times can be achieved by higher magnetic forces by using beads with a higher magnetic load; however, shorter times may lead to non-quantitative isolation, and beads with higher magnetic load are usually more dense and prone to rapid sedimentation. Therefore the quality control process in customizing a bead to a specific assay takes has to take into account the demands of the assay or isolation.

US Biologicals magnetic beads consist of iron oxide nanoparticles wrapped in a silica-bead. By tuning the size of the bead, and the percentage of the iron oxide nanoparticles we can tune the magnetic saturation, the speed to magnet, and the time in suspension (before sedimentation). Last but not least, the surface makes the difference! The superior surface chemistry enables high specific capture with low non-specific binding.

Antibody Capture

One-step antibody capture is now possible by using Magnetic separation systems in conjunction with Protein A and Protein G magnetic beads. Protein A and Protein G are recombinant proteins that bind with high affinity to the Fc portion of several classes and subclasses of immunoglobulins (IgGs) from a variety of species. Specific antigens are bound in a second step reversible towards the bound IgG. Subsequent wash and pH elution steps generate the purified target protein under native conditions. The combination of MagDetect high-yield MagSi protein A and G beads and magnetic separation systems results in large-scale antibody purification made simple. Separation occurs in just minutes. In addition, beads can be regenerated and re-used up to 10 times.

Main Applications

• High yield protein purification
• High yield antibody isolation
• Immunoprecipitation

Compared to other purification methods, such as streptavidin bead system, Protein G and A beads are capable of capturing the antibody in its native form (biotinylation is not necessary) and the binding is reversible. Furthermore, the superior surface chemistry blocks non-specific binding of residual proteins and other biomolecules. In this way, your target protein can be purified in a single step.

Advantages of MagDetect Protein A and G beads

• High specific binding capacity
• Choice in bead size (600nm and 1.0um)
• Choice of magnetic strength
• Customization of product possible
• Bead regeneration possible up to 10 times